What is the ruling on the action of Muslim merchants who take on commercial contracts (such as services and the like) for disbelievers in the lands of Islam?

Al-Halabi : What is the ruling on some Muslim merchants taking on commercial commitments, such as services, houses, and the like, for disbelievers in some of the lands of the Muslims?

The Shaykh : There is no doubt that such a question can be imagined to be ordinary trade, like bringing in goods that benefit Muslims or disbelievers, where they exchange benefits in a commercial manner. This is permissible because the work of the Companions (may Allah be pleased with them) in the time of the Messenger (peace and blessings be upon him) was that they would come to the land of Sham, buy and sell, and then return to the lands of the Muslims with their earnings. However, it is not so if the dealing with these disbelievers involves bringing in goods to them that the disbelievers use to aid against the Muslims. In this case, there is no doubt that this transaction is not permissible because it falls under the category of cooperating in evil. Allah the Mighty and Majestic says in the well-known verse: For example, it is not permissible for a Muslim in Palestine, for instance, who lives under the rule of the Jews, to be a worker in some of the military factories there, because that would be aiding the Jews against the Muslims and in fighting them when the confrontation occurs between the Jews and the Muslims. And so, by analogy, in this case, it is not permissible to buy goods for them or purchase for them.